If you didn’t understand everything, listen two more times with subtitles. (Click “English” in the box below the video.)

If you didn’t understand everything, read the transcript. (Click “Open Interactive Transcript”. There’s a box to the right of the video. In the top-right of the box, you can click the button.)

For any difficult parts, click on the words in the transcript. Then, you can listen to him say those parts again.

Now, if you’re really having trouble, you can listen with subtitles in your language. After you’ve listened with subtitles in your language, listen again in English.

Comprehension Questions Did you really understand this talk? Try to answer these questions. (Answers are below.)

At the beginning, there’s a slide show presentation. What problem does it present? What solution does it suggest?

What did Ferdinand Carre invent in 1858? Why couldn’t he build anything with it?

When was the Icyball invented? How did it work?

What problem did it have?

What is “psi”?

What is “computational work”?

Why was it important to find “non-toxic refrigerants that worked at very low vapor-pressures”?

What’s a rig?

What did they build?

How do you use the device to cool things?

What’s a prototype?

How big of a volume can it cool?

Will it work if it’s very hot outside?

How much will it cost if they build a lot of them?

How much will it cost if they don’t build a lot of them?

Discussion Questions Now discuss these questions.

What do you think of this product?

This video is from February 2007. Do you think these fridges have become popular?

What are some things people could do to make these fridges more popular?

Below the video on the TED site are many comments. Read some of the comments. Do you agree or disagree with them?

Answers

At the beginning, there’s a slide show presentation. What problem does it present? What solution does it suggest? The problem is that because 1.6 billion people don’t have refrigerators (or the fuel to use a refrigerator), they can’t keep medicine or food that needs to be cold. This makes their lives worse because, for example, there is more disease. The solution is a way to have a refrigerator that works without electricity, fossil fuels, or anything that you can’t get again easily.

What did Ferdinand Carre invent in 1858? Why couldn’t he build anything with it? He invented “absorption and refrigeration” which is a process that makes things colder by heating a gas. (Click here to learn more about it.) He couldn’t build anything with it because, in 1858, he didn’t have the right technology.

When was the Icyball invented? How did it work? It was invented in 1928. It works by heating ammonia and water. The Amonia moves through a tube to another container. When it cools, it comes back to the water and makes everything cold.

What problem did it have? It exploded because heating the ammonia created too much pressure.

What is “psi”? Pounds per square inch. It’s a measurement to say how powerful the air is pushing against its container. A container explodes when the psi is too powerful (like when a balloon explodes).

What is “computational work”? Basically, it means doing a lot of math.

Why was it important to find “non-toxic refrigerants that worked at very low vapor-pressures”? The problem with ammonia was that it exploded and was toxic (poisonous). For people to use the product, it couldn’t be poisonous or explode.

What’s a rig? Usually, it means the back part (trailer) of a truck. Here it just means a test item. It’s their first attempt at building the refrigerator.

What did they build? A low-pressure, non-toxic refrigerator.

How do you use the device to cool things? You heat it over a fire for 30 minutes, let it sit for an hour, and then put it inside something. Whatever you put it inside will get cold for 24 hours.

What’s a prototype? A common term for a test item, not the finished product.

How big of a volume can it cool? 15 liters.

Will it work if it’s very hot outside? Yes. It can work if it’s 30 degrees Celsius.

Popular Posts

::Expert English Services

Communication between cultures is a great thing. Nowadays, the easiest way to do that is with English. Stuart Mill English would like to help. We edit writing. We edit websites. We also help students write better by editing their essays and giving useful advice. Click on the image to visit our main website and learn more. Thanks for stopping by.